I've inserted 6000 listings using CSV import (I've defined about 8 fields for each listing) and 46 categories.
Category pages are loading very slow and I think it's a MySQL query problem.
Take a look on the following log (from MySQL slow query log) for a category page query. (Rows_examined: 36644164 !!! and 44 seconds)
# Query_time: 44 Lock_time: 0 Rows_sent: 5863 Rows_examined: 36644164 SELECT DISTINCT listing_id FROM wp_wpbdp_listing_fees WHERE listing_id NOT IN (SELECT listing_id FROM wp_wpbdp_listing_fees WHERE category_id IN (19) AND (expires_on IS NULL OR expires_on >= '2012-12-03 20:48:33'));
Please check this problem and send a feedback.
Thanks a lot.